The Putative Role Of Lymphocytic Infiltration In The Pathogenesis Of Tubal Pregnancy

Objective: Ectopic pregnancy(EP) is a pregnancy which occurs outside of the uterine cavity, and over 95% implants in the fallopian tube. The pathogenesis of tubal ectopic pregnancy(TEP) is complicated, and chronic inflammation is generally considered to be one of the major risk factors. However, research on the inflammation factors, especially on the inflammatory cells is still not enough.T lymphocytes and B lymphocytes are the most important chronic inflammatory cells. The existence of T lymphocytes which have cellular immune function depends on thymus. B lymphocyte with humoral immune function is not directly relying on thymus. There are several subsets in both T and B lymphocytes. CD3 and CD 20 is respectively the marker of T and B cell differentiation and is generally recommened for the use in the characterization of T and B lymphocyte.In clinical pathological practice, the chronic inflammatory cells infiltration with the main ingredient of lymphocytes were often observed in the fallopian tube of TEP, but the specific types and the roles of lymphocytes are still unclear. In this study, we took the routine pathological observation and comparatively analyzed the infiltration of inflammatory cell in tubal pregnancy and normal ovarian ducts, and further studied the types of lymphocytes with immunohistochemical methods. The results of this study may provide some help for the future treatment of tubal inflammation and prevention of tubal pregnancy.Methods:1 The cases of this study were from Department of Pathology, The Second Hospital of Hebei Medical University during 2012-2014. The paraffin embedded tubal tissue blocks of 52 cases of tubal pregnancy and 20 cases of normal fallopian tube were included. The average age of tubal pregnancy cases was 26(from 18 to 30 years old). The common clinical features were irregular vaginal bleeding, nausea and vomiting symptoms. The control normal fallopian tubes were all from patients without tubal abnormalities. The age of normal control was from 20 to 40 with an average of 32.5.2 Sections(4μm thick) were cut from paraffin blocks for HE staining.3 Detecting the expression of CD3 and CD20 in tissue samples by immunohistochemistry tests.4 Statistical analysisThe data was analysed by t test and χ2 test by SPSS13.0. Values were considered statistically significant when P<0.05Results: 1 The pathological morphology observation 1.1 Normal fallopian tubeFallopian tube wall was composed of mucosa, muscularis and serous. Tubal lumen surface coating mucosa, which was vertical alignmented, branch folded(called fold), and merged the oviduct umbrella. Mucosal epithelium was a single layer of columnar cells, mainly including ciliated and secretory cells. Muscle layer was composed of two layers of smooth muscle( inner circular layer and longitudinal layer).The outer surface of fallopian tube was serosa. Serous was wrapped by peritoneal, clad mesothelial cells. Occasionally, lymphocytes could be found in the mucous and muscular layer of fallopian tube, this could be a reaction to hemorrhage and necrosis(physiological salpingitis). 1.2 Tubal pregnancyMesenchymal cells in the fallopian tube could be arranged in small nests of decidual response, which was weaker than that in endometrium. Different degenerating degree of placenta villus and trophoblast cells could be found in the fallopian tube wall or blood clots which is the most direct evidence of tubal pregnancy.1.3 Chronic information in tubal pregnancyIn this study, 38 cases showed chronic inflammation in 52 cases of tubal pregnancy, the percentage was 75%. We could find big amounts of chronic inflammatory cells infiltrating in the tubal wall, in which, lymphocytes cells were the main ingredient, while neutrophils and eosinophilic granulocyte could be seen occasionally. However, in the rest of 13 cases, chronic inflammation was not obvious. 2 The results of immunohistochemistry 2.1 The expression of CD3 and CD20 in normal fallopian tube and tubal pregnancyBy immunohistochemistry, CD3+and CD20+lymphocytes could be seen occasionally in normal fallopian tube.CD3+T lymphocytes and CD20+B lymphocytes could both be found in tubal pregnancy. The mean percentage of CD3+Tymphocytes was 63.08%, which was significantly higher than that of CD20+B lymphocytes(21.33%)(P<0.05). Further analysis showed that cases with the main infiltration of CD3 was 32, while the cases with the main infiltration of CD20 was only 7, the former was significantly greater than the latter(P<0.05). The results prompt that T lymphocytes is more important in tubal pregnancy.Conclusions:1 The incidence of chronic inflammation was very high(up to 75%) in tubal pregnancy. The main inflammation cell was lymphocyte.2 The immune phenotype analysis showed that T and B lymphocytes could both be found in tubal pregnancy. However, T lymphocytes were the main cells which was uggested that cellular immunity is a momentous element in tubal pregnancy.